Search found 14 matches

by lcv
03 May 2019, 19:19
Forum: Parts Sourcing & Trading
Topic: j201 substitute
Replies: 28
Views: 8977

Re: j201 substitute

Hi, I just received some interfet j201 from Mouser. Quite expensive. Their parameters sit around Idss= 0.23 - 0.30mA, Vto=0.5 - 0.6V, I would say towards the lower spec limits (I didn't test all of them) https://www.mouser.it/ProductDetail/InterFET/J201?qs=sGAEpiMZZMv4z0HnGdrLjo0W1AxRZQdlr4Y9S0sHX3D...
by lcv
23 Dec 2018, 06:42
Forum: Boutique Stompboxes dissected...
Topic: Identifying Sanded Down Opamps
Replies: 4
Views: 1228

Re: Identifying Sanded Down Opamps

Hi Dirk You are right, the option I mentioned is more related to professional hacking, so it's not very practical. You'd need chemicals, access to a microscope and some intelligence work (e.g. dice pictures). Obviously for an analog IC designer visual inspection of a die is very informative. On a go...
by lcv
19 Dec 2018, 08:55
Forum: Boutique Stompboxes dissected...
Topic: Identifying Sanded Down Opamps
Replies: 4
Views: 1228

Re: Identifying Sanded Down Opamps

Decap the package and inspect the die directly is an option too
Lcv
by lcv
04 Feb 2018, 10:10
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Shredmaster versions
Replies: 0
Views: 1156

Shredmaster versions

Hi All The first Shredmaster schematics circulating years ago , showed an inverting configuration of the third opamp (just after the tone stack). Afterward original Marshall schematics were exclusively showing a non-inverting configuration for that opamp. Pls. if someone knows: Were those first sche...
by lcv
29 Dec 2017, 06:25
Forum: DIY Stompbox designs
Topic: Yes, another one about Boss SD-1 Buffer
Replies: 9
Views: 3989

Re: Yes, another one about Boss SD-1 Buffer

Hi Happycat
If you want to experiment, then do it. It' s just emitter follower.
Just make sure you don't fry your pickups, your question sort of implies that risk... :)
by lcv
16 Jul 2017, 16:02
Forum: Software Room
Topic: VeroRoute - Free layout software for Vero, Perf, & PCBs
Replies: 26
Views: 23673

Re: VeroRoute - Free layout software for Vero, Perf, & PCBs

Hi DrAlx Thanks for sharing this SW. I did spend some time experimenting some of its features ( I went through the tutorial [btw your NPN example won't bias correctly] , put together some components etc.) Now,apart from the SW itself , I have a fundamental issue on how the tracks, after auto-routing...
by lcv
20 Apr 2017, 09:26
Forum: DIY Stompbox designs
Topic: low pass and high pass filtering questions
Replies: 9
Views: 2750

Re: low pass and high pass filtering questions

Hi Jimi What is usually implemented as PSUs in tons of commercial stompboxes MUST be enough. Anyway you can't get anything quieter than a simple battery. So it must be picked up noise of some sort, but I don't believe that any rf noise can be so disruptive. My guess is that your friend simply has a ...
by lcv
19 Apr 2017, 13:29
Forum: DIY Stompbox designs
Topic: double shot of fuzzy goodness, unca ed's od/MONKEY BALLS
Replies: 11
Views: 3653

Re: double shot of fuzzy goodness, unca ed's od/MONKEY BALLS

Hi Jimi
Isn't AC 128 a PNP
I cannot relate this with the schematic's symbol...
Thanks!
Lcv
by lcv
25 Mar 2017, 15:35
Forum: DIY Stompbox designs
Topic: Stupid Pedal Trick: Photon Face (a si fuzzface that don't..)
Replies: 2
Views: 1226

Re: Stupid Pedal Trick: Photon Face (a si fuzzface that don'

I fell in love with it's sound, so I built it on a vero, now sharing.
Includes PSU from PJP's Schizoid schem.
Photon01.png
20170325_160550_3.jpg
by lcv
05 Mar 2017, 23:24
Forum: DIY Stompbox designs
Topic: presenting the Schizoid Face
Replies: 54
Views: 11798

Re: presenting the Schizoid Face

Hi Jimi this is a masterpiece just breadboarded it (the photon face) , input cap 47n, no cb caps , 2n3904 transistors hfe=200 played with my strat, sounds amazing, I like it very much It sounds true, trusty, friendly... Anyway, I'm going to build it on perfboard, I'll take some pictures. thank you t...
by lcv
11 May 2011, 09:06
Forum: Amplifiers
Topic: Marshall 5010 lead 30
Replies: 12
Views: 6832

Re: Marshall 5010 lead 30

Hi, It's not a trivial thing. First you have to redesign and replace the power supply (also mechanically), then it comes down to two things: 1) heatsinks recalculation 2) verification of the power dissipation/voltage rating/ current ratings of the rest of circuit. To me, since usually thees products...
by lcv
11 May 2011, 08:55
Forum: Amplifiers
Topic: Marshall 5010 lead 30
Replies: 12
Views: 6832

Re: Marshall 5010 lead 30

How is it possible that 5010 (10W) and Master Reverb 5203 (30W) with the same (identical!!!) power amplifiers (as shown in the schematics below), have different power? http://www.drtube.com/schematics/marshall/5010.gif http://www.drtube.com/schematics/marshall/5203.gif Can someone explain this? And...
by lcv
31 May 2010, 13:59
Forum: DIY Stompbox designs
Topic: Design Philosophy - Fuzz Face
Replies: 69
Views: 12939

Re: Design Philosophy - Fuzz Face

Just FYI, one thing I discovered by simulation (and then listening) is that in a maxed gain Si FF there is still a substantial negative feedback to the base of Q1 brought by the 100k resistor. In other words the 22u cap is by far not killing the Q2's emitter swing (as I had assumed since ever). To d...
by lcv
30 Jul 2009, 09:30
Forum: Software Room
Topic: Circuit Simulators
Replies: 4
Views: 3161

Re: Circuit Simulators

Hi, I've used (and still using) a lot LTspice http://www.linear.com/designtools/software/ to check a number of quantitative data about a given circuit such as frequency res., biasing, gains, shape of clipped waveforms etc. before actually build anything. I applied this mainly to dist./fuzz, but also...